Fasting and supplements before private thyroid tests

[userotc]

Whilst Ive emailed both Medichecks and Blue Horizon directly, I welcome your feedback regarding fasting and abstaining from supplementation e.g. Vitamin D, prior to having a private blood test for TSH, fT3, fT4 and antibodies. I note from earlier HU posts that it is advised to fast and abstain from vitamin D, B12 etc supplements for quite a while before the test but the BH website states in Extra Information "Fasting not required. No other special instructions".

It appears that there is little to choose between the 2 labs. BH seems to be a bit dearer at present but contributes to HU (maybe explains the price difference?)

The tests would be for my undiagnosed mother who has recently been taken off HRT

[Angel_of_the_North]

Eating can reduce TSH so is important if you are going to show your results to a TSH-obsessed doctor, TSH also falls during the day, so you want bloods taken as early in the am as possible. If the tests are purely for your own use, the important thing is to do them under the same conditions each time so you can compare results - always fasting (or not); same time of day.

[Hidden in reply to Angel_of_the_North]

Interestingly I did mine two weeks ago in the morning as usual but stupidly I’d taken my Levo and had my breakfast and TSH WAS 26

This week I had bloods done in the morning fasted and no Levo and TSH was 27

[Angel_of_the_North in reply to Hidden]

So looks as though you are very undermedicated. Might not seem as though 1 makes a difference to TSH, but it would have looked more if it had been the difference between 1 and 2. Takign levo before test will raise free T4 but probably not affect TSH

[userotc in reply to Angel_of_the_North]

I presume you were not replying to me with your comments re undermedicated?. My mother hasn't been diagnosed and takes no medication.

We are likely to try a more natural approach at least initially - including vit D supplements.

[Angel_of_the_North in reply to userotc]

No, I was replying to Snow2000

[Hidden in reply to Angel_of_the_North]

I am under medicated at the moment but that will change

[userotc in reply to Hidden]

Thanks. So maybe it doesn't really matter if you fast or not which both labs have now confirmed. What about vitamin supplements? Labs state no need to abstain.

BTW my mother's TSH was done at GP surgery 9 days ago at 1045h and was 0.72 nmol/l (0.3-5.0). So no fT3,4 etc - you know why!

Vitamin B12 was 401 ng/l (170-730), vit D 59.6 nmol/l (50-259), nothing else measured. She awaits consultation re results.

She came off HRT ~6 months ago after a nephrectomy in March and has had thyroid symptoms in past 6 weeks.

[SeasideSusie Remembering in reply to userotc]

Userotc

It can be useful to fast. If you want a diagnosis of Hypothyroidism then you need the highest possible TSH. Eating lowers TSH so an overnight fast, along with the earliest possible blood draw (no later than 9am) gives the highest TSH.

B12 should be at least 550. An extract from the book, "Could it be B12?" by Sally M. Pacholok:

"We believe that the 'normal' serum B12 threshold needs to be raised from 200 pg/ml to at least 450 pg/ml because deficiencies begin to appear in the cerebrospinal fluid below 550".

"For brain and nervous system health and prevention of disease in older adults, serum B12 levels should be maintained near or above 1000 pg/ml."

Vit D is recommended by the Vit D Council to be 100-150nmol/L.

Of course, nothing will be done for those Vit D and B12 levels because they're within range. Doctors aren't taught nutrition so as long as the result is in range then that's all they look at, they don't really know about optimal levels.

[SeasideSusie Remembering]

Userotc

The only supplement you need to leave off is Biotin or B Complex containing Biotin, that's because Biotin can affect results of thyroid tests.

Anything else, just take after the blood draw, no need to leave off for thyroid tests.

If testing iron, leave off iron supplements for a week.

If testing B12 then for a base result leave off for 4-5 months. Testing it whilst supplementing tells you if you're taking enough.

[userotc in reply to SeasideSusie]

Thanks, posts crossed! Feel free to comment on results to date.

[userotc in reply to userotc]

Apologies but I was wrong to say that only TSH, Vit D and B12 were measured. Fuller results and ranges are shown below, for completeness

Vit B12 = 401 ng/L. Range=170 - 730ng/L

Serum folate = 13 ug/L. Range=3-19 ug/L

Serum inorganic phosphate = 1.29 mmol/L. Range=0.8-1.5 mmol/L

Vit D = 59.6 nmol/L. Range=50-250 nmol/L

TSH = 0.72 nmol/L. Range=0.3-5.0 nmol/L

Note: Because of my mother's issues re kidney, other test results such as Biochemistry Battery tests (serum sodium etc), HbA1c and full blood count (red, white cell counts etc) were also reported.

I welcome any further comments, if appropriate. Hopefully a natural treatment focus (including diet and supplements) will help her.